The transportation of highly-temperature-sensitive pharmaceuticals and vaccines (hereinafter simply referred to as goods) is a major problem facing the distributers of those goods and the healthcare workers charged with administering those goods. If these goods are subjected to a temperature outside their acceptable temperature storage range, even for a short period of time, the goods will spoil. In some instances, spoiling will result in the goods being less effective than would otherwise be the case and in other instances, the goods may become dangerous to administer and they may represent a significant health risk to the intended recipient. Accordingly, it is essential that the distributers of the goods ensure that the goods are maintained within the desired temperature range from the time of production to the time of administration.
Once produced and prior to distribution to remote locations, the goods are stored at a central hub in an environmentally-controlled warehouse facility. In some cases, the goods are transported in environmentally-controlled vehicles to regional hubs where the goods are again stored in an environmentally-controlled warehouse facility before distribution. This part of the distribution chain is not seen as problematic. Of particular concern is the so-called “last mile” of the distribution chain where the goods are transported from a temperature-controlled facility to the location that they are to be administered. It is absolutely essential that the goods are maintained within their desired temperature range over the so-called “last mile”. In order to protect the goods over the last mile, they are often transported in portable temperature controlled containers.
The known temperature controlled containers typically comprise an insulated box constructed from polystyrene or other insulating material. The goods are carefully placed inside the box and the box is then often packed with ice (in hot climates) to keep the goods inside the insulated box cool. The goods are then transported over the “last mile” to the intended destination.
There are however, numerous problems with this solution. First of all, the temperature at which the goods are stored is not accurately controlled and there is no guarantee that the goods will be maintained within the desired temperature range. Secondly, it is difficult to determine precisely how much ice will be required for a given journey. If too much ice is packed into the container, the goods may freeze thereby spoiling the goods. On the other hand, if too little ice is packed into the container, the ice may have melted before the goods have been delivered and the goods may spoil prior to delivery. Thirdly, in some instances, the location will be very remote and may take several days to reach. In those instances it would be necessary to restock the ice on one or more occasions during the journey but this is often not possible. Furthermore, in those instances where the location is very remote, the container may experience significant variations in ambient temperature over the course of the journey, from extreme heat to extreme cold, and this is not addressed by the proposed solution.
There are however more complex solutions that involve the use of electromechanical systems to control the temperature of the goods in the portable container over the last mile. Electromechanical systems for refrigeration have existed for many years and while relatively efficient, they suffer from two main drawbacks. First of all, these systems are not considered to be particularly robust which makes it difficult for such systems to be reliable when exposed to the mechanical stresses experienced during journeys over rough terrain. Secondly, battery power must be relied upon and it is challenging to design lightweight, cost effective devices that will keep small quantities of product at correct temperatures for complete journey times. Generally speaking, many of the known designs that use electromechanical systems are too complex and therefore too expensive for the so-called “last mile” application addressed by this invention.
One device that has been proposed that attempts to address some of these problems is the device described in Chinese Patent Application No. CN103075856 in the name of Shanghai Polytechnic University. This device proposes to use a semiconductor cooling system and insulation comprising copper tubes filed with a phase changing material that will keep the contents cool when the semiconductor cooling system is not operational. Another device known to the applicant is GB2501223 in the name of Mars Incorporated. GB2501223 describes a cool storage cabinet used for storing chocolate in hot climates that has a thermoelectric cooling device and a phase change material. The phase change material is used to keep the contents of the cabinet cool during power outages when the thermoelectric cooling device is not operational.
It is an object of the present invention to provide a portable temperature controlled container that overcomes at least some of the problems with the known devices. It is a further object of the present invention to provide a useful choice to the consumer.